Final answer:
The best method to collect a stool specimen from a 5-year-old patient with dehydration, vomiting, and diarrhea is by using a stool ova and parasite (O&P) exam. Multiple stool samples should be collected over several days to increase detection chances.
Step-by-step explanation:
The best method to use to collect a stool specimen from a 5-year-old patient with dehydration, vomiting, and diarrhea is by using a stool ova and parasite (O&P) exam. This involves direct examination of the stool sample for the presence of cysts and trophozoites of parasites. It is important to collect multiple stool samples over several days to increase the chances of detecting any parasites that may be present.